Should Pain Treatments Target the Brain or Body?

Pain treatments often target either the brain or body, but data show that treatments often benefit both.

LAS VEGAS—Available pain treatments target the body, brain, or more commonly both, and matching treatments to pain mechanisms will improve outcomes for patients with pain, according to a presentation at PAINWeek 2016.

Roger B. Fillingim, PhD, a distinguished professor at the University of Florida (UF) College of Dentistry and director of the UF Pain Research and Intervention Center of Excellence, noted that, while pain conditions are not typically thought of as "peripheral or central," phenotyping each patient and having an idea of what specifically is being targeted, peripheral or central pain, can facilitate treatment choices.

Dr Fillingim explained there are numerous pain medications available — according to one website, 537 in all — that fall under various headings, including anesthetics, antidepressants, opioids, and others. Procedural options for addressing pain are also numerous, ranging from surgery, to physical modalities such as light therapy and massage, to psychological interventions like biofeedback, to alternative therapies such as acupuncture. All of these interventions have varying success, which is often dependent upon the patient.

As an example of how patients cope with pain and interventions differently, Dr Fillingim described a study that he and his colleagues conducted that looked at patients who were tested by dropping their hands into ice cold water after they had been subjected to rising heat. "Before and after we asked them to stick their other hand in ice cold water. For some patients, there was a relief response, but that only happened for our low distress group. All of the other psychological profiles failed to show a pain inhibitory response." For this reason other factors, including psychological profiles, should be considered when deciding upon treatment approaches, he noted.

Studies have also demonstrated that procedural interventions can have a direct impact on the brain. Dr Fillingim described a study by Gwilym and associates that examined data on 16 patients who had underwent hip arthroplasty.2 In that study, the researchers concluded that "gray matter volume decreases within the left thalamus in the presence of chronic pain and disability in patients with hip ostearthritis. The results also show that these thalamic volume changes reverse after hip arthroplasty and are associated with decreased pain and increased function."

"So did this treatment target the body or the brain?" Dr Fillingim asked the audience. "Inevitably, what we do is we end up treating both."

References

Fillingim RB. The brain or the body: what is the target for pain treatment? Presented at: PAINWeek 2016. September 6-10, 2016; Las Vegas, NV.